Fluid-actuated hammer tool



Dec. 7 1926.

. vF. H. THOMAS FLUID ACTUATED HAMMER TOOL 2 Sheeis-Sheet 1 Filed June20, 1925 INVENTOR.

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Patented Dec. 7, 1926.

- UNITED STATES PATENT oil-Pica;

FLOYD H. THOMAS, 015 MILAN, PENNSYLVANIA, ASSIGNOR 1'0 INGERSOLL-RANDGOM- OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY. I

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' application filed June 20, 1925. Serial No. 38,435.

' This invention relates'fto fluid actuated hammer tools in which theimplement to' which blows of impact are imparted by the reciprocatinghammer may be of any desired form. The machine may be a sand rammer,coal pick, rock drill, or of some other type, in which the pressurefluid is controlled by a distributing valve or valves,

but in the resent instance the particular type of machine to which thisinvention relates has a main piston controlled. exhaust, an inlet valve,and a compression relief valve controlling auxiliary exhaust ports.

The objects of the invention are to construct both the inlet andcompression relief valves in a simple manner and enable both valves tobe located in compact and easil accessible form ina convenient positionwit relation to the cylinder, preferably in a valve box at the rear endof the cylinder.

between the cylinder and back head, although the location may bevaried'as desired.

Another ob'ect' of the invention is to make the mac ine easy to holdduring operation.

To these ends the invention is shown in one of its preferred forms inthe accompanying drawings, in which Figure 1 is a longitudinal sectionalelevation of so much of a fluid actuated hammer tool as will serve toillustrate the invention, this view being taken on the line 1-1 ofFigure 2 looking in the direction of the arrows,

Figure 2 is a transverse top plan view on the line 2-2 of Figure 1looking in the direction of the arrows,

Figure 3 is an enlarged sectional elevation taken on the line 3-3 10fFigure 2 looking in the direction of the arrows with the exception thatthe valves have oscillated so that the piston is moving rearwardly'instead of forwardly as shown in Figure 1.

Figure 4 is a sectional elevation. taken through the inlet valve on theline 4-4 of Figure 2 looking in the direction of the arrows,

Figure through the compression relief valve on the line 5-5 of Figure 2looking in the direction of the arrows,

Figures 6 and 7 are views similar to Figures 4 and 5 with the valves andpiston in 5 is a sectional elevation taken a different positioncorresponding to the position shown in Figure 3, and Y Figures 8 and 9are similar views showing a different position of the parts Referring tothe drawings, the cylinder A is provided with the piston B having thehead C and the forward extending shank Il.) adapted to impart blows ofimpact to the shank E of a suitable implement. Pressure fluid, as forinstance, compressed air, is supplied through the supply passage F inthe back head G and themain exhaust H of the cylinder is in thisinstance controlled by thepiston.

A supply passage J for fluid under pres- I sure communicates at the ortK with the forward end of the cylin er and suitable means are providedin accordance withthis invention for controlling the distribution ofpressure fluid to both the rearward and forward ends of the cylinder.

In the present instance, a valve box'comprising the plate or block L,the separator or spacer O and the cover P is located between thecylinder A and the back head G, and the inletvalve Q and the compressionrelief valve R are located in this valve box.

The valve box plate L is formed with the inlet port S communicating withthe inlet passa e J leading to the forward end of the cylin er and isalso provided with the inlet port T leading to the rearward end of thecylinder; The valve box plate L is also provided with-the ports U and Vwhich act as auxiliary exhaust ports. The ports S and U are connected bya cross passa e W and the ports T and V are connected by a cross passageX and these cross passages as shown are in the form of grooves milled orotherwise cut in the plate L and they are covered over by the solidcentral portion Y of the separator plate O'of the valve ox. Theseparator or spacer plate 0 of the valve box is suitably formed in thisinstance with rectangular valve chambers a and b in which oscillatingvalves Q and R are located. These valves may be in the form ofrectangular plates tapering substantially uniformly in each directionfrom the median or central portions so that they will rock or oscillateand they may be provided pins e extend.

The valve box cover P is formed with the inlet ports f and f controlledby the'inlet valve Q. and two auxiliary exhaust ports g and hcommunicating with the atmosphere preferably at opposite ends of adiameter of the valve box cover P and these auxiliary exhaust ports orcompression relief ports g and h are controlled by the compressionrelief valve R as it oscillates. Since the passage J in the cylinder ofthe machine communicates by means of the cross passage W In theoperation of the machine, let it be assumed that the piston is moving onits forward stroke as indicated in Figures :1, 2, 4

and 5. As the piston was starting andbefore it reached and covered thefree exhaust port H the forward end of the cylinder was at atmosphericpressure and conse uently there was atmospheric pressure un er theopposite end of the inlet valve Q, through the passage J and; port S.After the piston has covered the free exhaust H compression in theforward end of the cylinder is relieved through the passage J, port S,cross passage W, port U and thence out through the auxlliary exhaustthrough the end of the compression relie valve R which is in theposition indicated in Figure 5 since pressure fluid under workingpressure in the rear end of the cylinder maintains the compresion reliefvalve R in the position closing the opposite auxiliary exhaust h.

When the piston overruns the free exhaust H as indicated in Figures 6and 7, the ressure in the rearward end of the c lin er is dropped andthe live pressure flui through the inlet port 7 in the valve box on topof the inlet valve Q in combinationwith the slight compression in thefront end of the cylinder exerted upon the under side of the valve Qthrough the port S rocks the valve to close the cylinder inlet port Tand open the port S communicatin by the passage J with the forward endof t e cylinder so' that the piston starts on its rearward. travel. Atthe same time live pressure fluid is admitted through the inlet port S,cross passage W and port U to the under side of the com res- 'sionrelief valve R at one end thus oscillate cylinder a I valve boxcentrally in line with the cyl'nden at its rearward end and having valvechamhers located side by side valve seats in said chambcrsarranged insubstantially the same plane transverse to the axis of the cylinder, avalve box cover, two separate oscillating plate valves located side byside in substantially the same plane in said valve box'chambers, one aninlet valve and the other an.

auxiliary exhaust valve, inlet ports for both ends of the cylinder inthevalve seat of one valve box chamber controlled by the inlet valve,separate auxiliary exhaust ports in the valve box cover controlled bythe auxiliary exhaust valve, and cross passages in the valve boxconnecting the said inlet ports with said auxiliary exhaust ports. I

2. In a fluid actuated hammer tool, the combination of a cylinder andpiston, a main piston controlled exhaust for the cylinder, a

at its rearward end, said valve box including a valve block and a cover,valve chambers located side by side in the said block, valve seats insaid chambers arranged in substanof the cylinder, two separateoscillating plate valves located side by side in substantlally the sameplane in saidvalve box chambers, one an inlet valve and the other anauxiliary exhaust valve, inlet ports for both ends of the cylinder inthe valve seats of one valve valve box centrally in line with thecylinder tially the same plane transverse to the axis box chambercontrolled by the inlet valve, 7

separate diametrically opposite auxiliary exhaust. ports in the valvebox cover controlled by the auxiliary exhaust valve, and cross 7passages wholly in the said valve block connecting's'aid inlet portswith the respective" auxiliary exhaust ports for each end ofthecylinder.

In testimony whereof I have signed this I specification. j I

a 1- FLQYD H. THOMAS.

